This invention relates to a continuous casting cut-off device and more particularly to a carriage mounted torch-type apparatus for cutting a continuously moving metal casting in the form of a bar into short pieces or billets.
In known continuous casting procedures, the metal strand or bar often is discharged downwardly and then curved into a horizontal position where the bar moves continuously along a bed.
Previously known devices for cutting a horizontally moving bar have included a large ponderous carriage movable along the bed and providing a vertical support leg on each side of the bed with a large bridge spanning the space between the upper ends of the legs and disposed over the bar. The cutting torch mechanism was suspended from the carriage, the latter also mounting a bar clamping mechanism. When the clamping mechanism was clamped to the moving bar, the carriage and torch were carried along with the bar while the torch would cut through the bar. At the end of the cut, the clamping mechanism was released from the bar and the carriage was manually or selectively actuated to return it to its starting position.
Such known devices have been subject to a number of disadvantages.
For example, in the event of a malfunction or breakdown in the bar clamping mechanism, the torch cutting mechanism or other parts related to the carriage, the cutting operation has to be terminated for repair work. Nevertheless, the casting or bar must continue to move along the bed during repairs, due to the nature of the continuous casting process. Since the known devices do not lend themselves to particularly fast repairs, the amount of uncut metal which is wasted can be quite large.
Furthermore, vertical or horizontal deviations in the moving bar can cause problems in accuracy of cut and the like.
Also, it is desirable to return the transversely movable cutting torch to its start position as fast as possible to prepare the torch for the next cut. In the known devices, the torch return has been relatively slow.
In addition, manual or selective carriage return is not particularly fast and efficient and the known mechanisms are usually quite costly.